Hydrocarbon-in-water purification system

ABSTRACT

A hydrocarbon-in-water purification system includes a high capacity hydrocarbon absorber stage having a high capacity hydrocarbon absorber material and an inlet configured to receive a hydrocarbon-in-water dispersion from a fuel system. A polishing hydrocarbon absorber stage is in liquid communication and downstream of the high capacity hydrocarbon absorber stage including polishing activated carbon. The high capacity hydrocarbon absorber material has a greater saturation capacity than the polishing activated carbon and the polishing activated carbon has a greater polishing capacity than the high capacity hydrocarbon absorber material. A method for controlling and managing the evacuation of water from the hydrocarbon-in-water purification system includes tracking the purification state of water volumes and the bed loading states of purification beds defined in the water filter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/558,614, filed 15 Sep. 2017, which is the § 371 U.S. National Stageof International Application No. PCT/US2016/022901, filed 17 Mar. 2016,which claims the benefit of U.S. Provisional Application No. 62/134,279,filed 17 Mar. 2015, the disclosures of which are incorporated byreference herein in their entireties.

The present disclosure relates to hydrocarbon-in-water purificationsystems and methods, and particularly those that remove hydrocarbonsfrom water with a high capacity absorber element upstream from apolishing absorber element.

BACKGROUND

Water contamination in fuel is a concern as it affects the performanceand operation of engines. Water contamination can cause various problemsincluding fuel filter plugging, fuel starvation, damage of enginecomponents through cavitation and corrosion, and promotion ofmicrobiological growth, for example.

Various devices have been employed to reduce water contamination infuel. By way of example, coalescing and separating devices have beenemployed to first cause the emulsified water to coalesce into largerdroplets and then remove the enlarged droplets from the fuel stream. Aremoved or drained hydrocarbon-in-water dispersion or emulsion stream isan output from this water from fuel separator system.

Recent efforts have been focused on reducing air pollution caused by thecombustion of hydrocarbon fluids. Diesel fuels have been refined withreduced amounts of sulphur to meet diesel engine emission controlregulations. However, these low-sulphur diesel fuels have necessitatedthe use of other additives. By way of example, surfactants have beenadded to low-sulphur diesel fuels to maintain sufficient lubricity ofthe diesel fuel for the engine. Surfactants have also the effect ofstabilizing hydrocarbon-in-water emulsions or dispersions as they lowerthe interfacial tension between water and hydrocarbons.

SUMMARY

The present disclosure relates to hydrocarbon-in-water purificationsystems and methods, and particularly to those that remove hydrocarbonsfrom water with a high capacity absorber element upstream from apolishing absorber element, among other aspects.

In many embodiments a hydrocarbon-in-water purification system includesa high capacity hydrocarbon absorber stage having a high capacityhydrocarbon absorber material and an inlet configured to receive ahydrocarbon-in-water dispersion from a fuel system. A polishinghydrocarbon absorber stage is in liquid communication and downstream ofthe high capacity hydrocarbon absorber stage. The polishing hydrocarbonabsorber stage includes polishing activated carbon. The high capacityhydrocarbon absorber material has a greater saturation capacity than thepolishing activated carbon and the polishing activated carbon has agreater polishing capacity than the high capacity hydrocarbon absorbermaterial.

In further embodiments, an engine fuel and water separation systemincludes a fuel and water separator system fluidly connected to anengine fuel line and having a water drain outlet. A hydrocarbon-in-waterpurification system, described herein, is in fluid communication withthe water drain outlet.

In still further embodiments, a method includes forming ahydrocarbon-in-water dispersion from a fuel system and passing thehydrocarbon-in-water dispersion through a high capacity hydrocarbonabsorber stage. The high capacity hydrocarbon absorber stage includes ahigh capacity hydrocarbon absorber material that removes at least aportion of hydrocarbon from the dispersion to form a permeate that issubstantially water. Then, passing the permeate through a polishinghydrocarbon absorber stage. The polishing hydrocarbon absorber stageincludes polishing activated carbon to adsorb hydrocarbon and form apolished water stream. The high capacity hydrocarbon absorber materialhas a greater saturation capacity than the polishing activated carbonand the polishing activated carbon has a greater polishing capacity thanthe high capacity hydrocarbon absorber material.

In various embodiments, a method includes determining whether apurification state of a dischargeable water volume in a finalpurification bed in a water filter is clean or not clean. The waterfilter contains one or more water volumes and a plurality ofpurification beds arranged from a first purification bed to the finalpurification bed such that the first purification bed receives new waterintroduced into the water filter from a water collection reservoir andthe final purification bed discharges water from the water filter. Theone or more water volumes reside in the plurality of purification beds.The method further includes introducing a new water volume into thefirst purification bed in response to determining that the dischargeablewater volume is clean. Introducing the new water volume may move each ofthe one or more water volumes in the water filter such that thedischargeable water volume leaves the final purification bed and a nextdischargeable water volume of the one or more water volumes enters thefinal purification bed. The method also includes tracking a purificationstate associated with the next dischargeable water volume in response toa residence time of the next dischargeable water volume in at least oneof the purification beds, and tracking a bed loading state associatedwith the at least one of the purification beds in response to theresidence time.

In additional embodiments, a method includes introducing a new watervolume into a first purification bed of a water filter. The water filtercontains one or more water volumes and a plurality of purification bedsarranged from the first purification bed to a final purification bedsuch that the first purification bed receives new water introduced intothe water filter from a water collection reservoir and the finalpurification bed discharges water from the water filter. The one or morewater volumes may reside in the plurality of purification beds. Themethod may further include updating a purification bed tracker definingan associated purification bed corresponding to one of the plurality ofpurification beds. The purification bed tracker maintains a currentresidence time of a current water volume residing in the associatedpurification bed, a current purification state of the current watervolume, and a current bed loading state of the associated purificationbed. Each of the plurality of purification beds is associated with adifferent purification bed tracker and a different water volume. Also,the method includes updating the current purification state of thepurification bed tracker associated with the first purification bed tounclean.

In various further embodiments, a method includes introducing a newwater volume into a first purification bed of a water filter. The waterfilter contains one or more water volumes and a plurality ofpurification beds arranged from the first purification bed to a finalpurification bed such that the first purification bed receives new waterintroduced into the water filter from a water collection reservoir andthe final purification bed discharges water from the water filter. Theone or more water volumes reside in the plurality of purification beds.The method further includes updating a water volume tracker defining anassociated water volume corresponding to one of the water volumes. Thewater volume tracker maintains a current residence time of theassociated water volume, a current purification state of the associatedwater volume, a current purification bed in which the associated watervolume resides, and a current bed loading state of the currentpurification bed. Each of the one or more water volumes is associatedwith a different water volume tracker and a different purification bed.Still further, the method includes creating a water volume trackerassociated with the new water volume with the current purification stateof the new water volume set to unclean.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various embodiments of the disclosurein connection with the accompanying drawings, in which:

FIG. 1 is a schematic diagram view of a hydrocarbon-in-waterpurification system;

FIG. 2 is a schematic diagram view of an engine fuel and waterseparation system; and

FIG. 3 is a schematic diagram view of another hydrocarbon-in-waterpurification system.

FIG. 4 is a schematic diagram view of an engine system having ahydrocarbon-in-water purification system.

FIG. 5 is a schematic diagram view of a process for managing theevacuation of water from the engine system of FIG. 4.

FIG. 6 is a schematic diagram view of a fuel water separator and a waterfilter of the engine system of FIG. 4.

FIG. 7 is a schematic diagram view of a controller of the engine systemof FIG. 4.

FIG. 8 is a schematic diagram view of a process for checking waterevacuation conditions of the process of FIG. 5.

FIG. 9 is a schematic diagram view of a process for maintaining apurification bed tracker.

FIG. 10 is a schematic diagram view of a process for maintaining a watervolume tracker.

The schematic drawings presented herein are not necessarily to scale.Like numbers used in the figures refer to like components, steps and thelike. However, it will be understood that the use of a number to referto a component in a given figure is not intended to limit the componentin another figure labeled with the same number. In addition, the use ofdifferent numbers to refer to components is not intended to indicatethat the different numbered components cannot be the same or similar.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which are shown byway of illustration several specific embodiments of devices, systems andmethods. It is to be understood that other embodiments are contemplatedand may be made without departing from the scope or spirit of thepresent disclosure. The following detailed description, therefore, isnot to be taken in a limiting sense.

All scientific and technical terms used herein have meanings commonlyused in the art unless otherwise specified. The definitions providedherein are to facilitate understanding of certain terms used frequentlyherein and are not meant to limit the scope of the present disclosure.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise.

As used in this specification and the appended claims, the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

As used herein, “have”, “having”, “include”, “including”, “comprise”,“comprising” or the like are used in their open ended sense, andgenerally mean “including, but not limited to.” It will be understoodthat the terms “consisting of” and “consisting essentially of” aresubsumed in the term “comprising,” and the like.

Any direction referred to herein, such as “top,” “bottom,” “left,”“right,” “upper,” “lower,” “above,” below,” and other directions andorientations are described herein for clarity in reference to thefigures and are not to be limiting of an actual device or system or useof the device or system. Many of the devices, articles or systemsdescribed herein may be used in a number of directions and orientations.

The term “hydrocarbon” refers to oil or fuel materials that areprimarily formed of saturated or unsaturated molecules with thirty orless carbon atoms.

The phrase “hydrocarbon-in-water emulsion” refers to an emulsion ordispersion where water is the continuous phase and hydrocarbon is thedispersed or discontinuous phase.

The term “absorption” refers to the removal process of hydrocarbons fromwater and includes absorption, adsorption, or the like processes ofremoval of hydrocarbons from water.

The phrases “high capacity hydrocarbon absorber material” and “highcapacity material” refer to a material that does not need to clean waterto the intended cleanliness, but instead has properties that lead tohigh saturation capacities. For example, when challenged with 2500 ppmB5-in-water emulsion or dispersion (B5=5% biodiesel blend) thesaturation capacity of these materials is preferably greater than 750 mgof hydrocarbon per gram of material or greater than 1000 mg ofhydrocarbon per gram of material. Preferred saturation capacities willvary depending on the challenge fluid concentration and makeup.

The phrase “polishing hydrocarbon absorber material” and “polishingmaterial” refer to a material that can purify water down to the intendedcleanliness over a wide range of incoming challenge waterconcentrations. Preferably, these materials have high loadingcharacteristics at the intended target cleanliness. For example, whenchallenged with 2500 ppm B5-in-water emulsions or dispersions, with atarget cleanliness of 2 ppm, these materials have a preferred loading orpolishing capacity of greater than 25 mg of hydrocarbons per gram ofmaterial or greater than 50 mg of hydrocarbon per gram of material.Preferred loading characteristics depend on challenge fluidconcentration and makeup, and on target cleanliness

The present disclosure describes water purification systems andparticularly to systems that remove hydrocarbons from water with a highcapacity absorber element upstream from a polishing absorber element,among other aspects. The high capacity absorber element removed at leasta portion of the hydrocarbon from a hydrocarbon in water dispersion toform a permeate. The permeate is then passed through the polishingabsorber element to form a polished water stream. The polished waterstream can have less than 5 ppm of hydrocarbons or less than 2 ppm orhydrocarbons or less than 1 ppm of hydrocarbons. In many embodiments thehigh capacity absorber element is activated carbon and/or a polymericmaterial such as polyurethane and the polishing absorber stage isactivated carbon. The high capacity hydrocarbon absorber material has agreater saturation capacity than the polishing activated carbon and thepolishing activated carbon has a greater polishing capacity than thehigh capacity hydrocarbon absorber material. The high capacityhydrocarbon absorber stage and the polishing hydrocarbon absorber stagemay be contained within a single housing. While the present disclosureis not so limited, an appreciation of various aspects of the disclosurewill be gained through a discussion of the examples provided below.

Fuel cleanliness requirements for fuel injection systems are demandingin order to ensure reliable engine performance. To a large degree, fuelfiltration is responsible for meeting the fuel cleanliness requirementsassociated with the control of abrasive particles and non-dissolvedwater. These fuel filters can coalesce at least a portion of theentrained water from the fuel stream and form a fuel-in-water dispersionor emulsion waste stream.

FIG. 1 is a schematic diagram view of a hydrocarbon-in-waterpurification system 10. FIG. 3 is a schematic diagram view of anotherhydrocarbon-in-water purification system 100. The hydrocarbon-in-waterpurification system 10 includes high capacity hydrocarbon absorber stage30 containing a high capacity hydrocarbon absorber material 36 and aninlet 21 configured to receive a hydrocarbon-in-water dispersion 22 froma hydrocarbon-in-water dispersion source. The high capacity hydrocarbonabsorber material 36 removes at least a portion of the hydrocarbon andforms a permeate that is substantially water. Permeate exits the highcapacity hydrocarbon absorber stage 30. A polishing hydrocarbon absorberstage 40 is in liquid communication and downstream of the high capacityhydrocarbon absorber stage 30. Permeate 32 enters the polishinghydrocarbon absorber stage 40 that includes a polishing hydrocarbonabsorber material 46. The polishing hydrocarbon absorber material 46removes the remaining hydrocarbon to achieve a purified water stream 42exiting the polishing hydrocarbon absorber stage 40. The polishinghydrocarbon absorber stage 40 can include activated carbon, for example.

Preferably, the high capacity hydrocarbon absorber material 36 has agreater saturation capacity (q_(sat)) than the polishing activatedcarbon 46 and the polishing activated carbon 46 has a greater loading orpolishing capacity (q_(t)) than the high capacity hydrocarbon absorbermaterial 36. The high capacity hydrocarbon absorber material 36 may havean, at least 10% greater or at least 25% or greater or at least 50%greater or at least 100% greater saturation capacity (q_(sat)) than thepolishing activated carbon 46. The polishing activated carbon 46 mayhave an, at least 10% a greater or at least 25% greater loading orgreater or at least 50% greater or at least 100% greater polishingcapacity (q_(t)) than the high capacity hydrocarbon absorber material36.

FIG. 3 illustrates an embodiment of a dual absorber 100 where the highcapacity hydrocarbon absorber stage material 36 forms a containerdefining a void space and the polishing hydrocarbon absorber material 46(for example, activated carbon) is disposed in the void space. The highcapacity hydrocarbon absorber stage material 36 forming the containercan be contained in a housing 13 having an inlet 22 (supplying the fuelin water dispersion) and an outlet 42 (purified water stream). In manyof these embodiments the high capacity hydrocarbon absorber stagematerial 36 is a non-woven fiber or fabric layer that is formed of apolymeric material described below.

FIG. 2 is a schematic diagram view of an engine fuel and waterseparation system 11.

The engine fuel and water separation system 11 includes a fuel and waterseparator system 50 (fuel water separator) fluidly connected to anengine fuel line 12 and having a water drain outlet 23 and a filteredfuel outlet 24. A hydrocarbon-in-water purification system 10, 100 is influid communication with the water drain outlet 23.

In many embodiments the hydrocarbon-in-water dispersion source is fuelfilter element 50 that can filter out particulates from the fuel flowand coalesce water and form a hydrocarbon-in-water dispersion stream.The fuel filter element 50 forms a portion of a fuel system such asthose used in a diesel engine such as a vehicle engine, for example.

The hydrocarbon-in-water purification system 10, 100 may be containedwithin a single housing. The high capacity hydrocarbon absorber stage 30and the polishing hydrocarbon absorber stage 40 are contained within asingle housing 13, a filter housing, for example. The high capacityhydrocarbon absorber stage 30 may defines a first volume 36 (of highcapacity material) and the polishing hydrocarbon absorber stage 40 maydefine a second volume 46 (of polishing material) and the first volume36 and the second volume 46 are contained within a filter housing 13.

The high capacity hydrocarbon absorber stage 30 and the polishinghydrocarbon absorber stage 40 may be physically separated from eachother when contained within a single housing 13. A porous dividingelement 15 may separate the first volume 36 from the second volume 46.

The porous dividing element 15 may prevent or reduce mixing or diffusionof the first volume 36 (of high capacity material) with the secondvolume 46 (of polishing material). The porous dividing element 15 may befixed to the filter housing 13. The porous dividing element 15 mayinclude a plurality of apertures. The apertures may be sized to preventthe high capacity material and the polishing material from passingthrough the porous dividing element 15. The apertures may be smallerthan the particle size of the high capacity material and the polishingmaterial. The porous dividing element 15 may be a screen element orporous metal layer.

The porous dividing element 15 may be a porous non-woven layer ornon-woven fabric layer. The non-woven layer 15 may be formed of apolymeric material such as polyethylene, polypropylene, polyurethane,polyester, and combinations thereof. These polymeric materials may alsoabsorb hydrocarbons and be a hydrocarbon absorber material. The porousdividing element 15 may be a polyurethane non-woven layer. The porousdividing element 15 may be an extruded layer such as a polymeric screenformed of a polymeric material such as polyethylene, polypropylene,polyurethane, polyester, and combinations thereof. These polymericmaterials may also absorb hydrocarbons and be a hydrocarbon absorbermaterial.

The hydrocarbon-in-water purification system 10, 100 includes a highcapacity hydrocarbon absorber stage 30 containing a high capacityhydrocarbon absorber material 36 and an inlet 23 (fluidly coupled to thewater drain outlet 23 of the fuel and water separator system 50) toreceive a hydrocarbon-in-water dispersion 22 from a hydrocarbon-in-waterdispersion source 50. The high capacity hydrocarbon absorber material 36removes at least a portion of the hydrocarbon and forms a permeate thatis substantially water. Permeate exits the high capacity hydrocarbonabsorber stage 30. A polishing hydrocarbon absorber stage 40 is inliquid communication and downstream of the high capacity hydrocarbonabsorber stage 30. Permeate enters the polishing hydrocarbon absorberstage 40 that includes a polishing hydrocarbon absorber material 46. Thepolishing hydrocarbon absorber material 46 removes the remaininghydrocarbon to achieve a purified water stream 42 exiting the polishinghydrocarbon absorber stage 40. The polishing hydrocarbon absorber stage40 can include activated carbon, for example.

In some embodiments, the hydrocarbon-in-water purification system 10,100 can include an antimicrobial agent. For example, one or more of thehigh capacity hydrocarbon absorber stage 30 or polishing hydrocarbonabsorber stage 40 can include an antimicrobial agent. The antimicrobialagent can be any useful material or compound that inhibits microbegrowth or kills microbes. Exemplary antimicrobial agents include silver,copper, organic biocides (such as quaternary amines, for example),ozone, or UV light.

In many embodiments, the hydrocarbon-in-water dispersion or emulsion hasa hydrocarbon content of at least 500 ppm or at least 1000 ppm or atleast 2,000 ppm or at least 5,000 ppm. The permeate has a hydrocarboncontent of less than 500 ppm or less and 250 ppm or less than 100 ppm.The polished water stream has a hydrocarbon content of less than 5 ppmor less than 2 ppm, or less than 1 ppm.

In other embodiments, the hydrocarbon-in-water dispersion or emulsionhas a hydrocarbon content of at least 100 ppm or at least 250 ppm or isin a range from 100 ppm to 500 ppm. The permeate has a hydrocarboncontent of less than the hydrocarbon-in-water dispersion or emulsion.The polished water stream has a hydrocarbon content of less than 5 ppmor less than 2 ppm, or less than 1 ppm.

Hydrocarbon Absorbing Material

The hydrocarbon absorbing material includes any material capable ofabsorbing hydrocarbons. Exemplary hydrocarbon absorbing materialincludes polymeric material, activated carbon, or both. Thehydrocarbon-in-water dispersion first contacts a high capacityhydrocarbon absorbing material prior to contacting a polishinghydrocarbon absorbing material. It has been found that the overall lifeof the hydrocarbon absorbing element can be prolonged by having the highcapacity hydrocarbon absorbing material upstream of the polishinghydrocarbon absorbing material.

The relationship between equilibrium concentration and carbon loadingcan be described by an adsorption isotherm. Three of the most widelyused models of adsorption are the Freundlich, Langmuir, and BET(Brunauer, Emmett, and Teller) isotherms. Of these, the empiricalFreundlich Isotherm expression best describes the loading behavior ofactivated carbon over a wide range of challenge conditions and loadingamounts. The Freundlich isotherm expression is:

$q = {\frac{x}{m} = {K_{f}c_{e}^{\frac{1}{n}}}}$where q is the adsorbent loading in milli-grams of adsorbate per gram ofadsorbent (x/m), c_(e) is the equilibrium adsorbate concentration insolution, and K_(f) and 1/n are the isotherm parameters that aredependent on the adsorbate, adsorbent, and temperature.

The Freundlich Isotherm expression can be used to determine theadsorbent loading at a particular target equilibrium adsorbateconcentration. When the equilibrium adsorbate concentration (c_(e)) isequal to the incoming adsorbate concentration (c₀) the material isexhausted. The loading capacity under these conditions is called thesaturation capacity or q_(sat). The saturation capacity of a materialvaries with different incoming adsorbate concentrations. A material thathas high saturation capacity is called a high capacity hydrocarbonabsorber material or high capacity material.

In most purification applications the target adsorbate concentrationleaving the element (c_(t)) is less than the incoming adsorbateconcentration. In this case, the adsorbent loading determined from theFreundlich Isotherm expression at the intended target adsorbateconcentration is deemed the polishing capacity or q_(t). The polishingcapacity of a material varies with different incoming adsorbateconcentrations and target adsorbate concentrations. The polishingcapacity is generally less than the saturation capacity. A material thathas high polishing capacity is called a polishing hydrocarbon absorbermaterial or polishing material.

Preferably, the high capacity hydrocarbon absorber material has agreater saturation capacity (q_(sat)) than the polishing hydrocarbonabsorber material and the polishing hydrocarbon absorber material has agreater polishing capacity (q_(t)) than the high capacity hydrocarbonabsorber material. The saturation capacity (q_(sat)) and polishingcapacity (q_(t)) is determined with the same incoming adsorbateconcentration.

A hydrocarbon-in-water purification system containing separate sectionsof a high capacity material followed by a polishing material has anincreased lifetime over a similar sized system of a single material. Inparticular, a filter housing containing separate sections of a highcapacity material followed by a polishing material can have an increasedlifetime over a similar sized filter housing of a single material. Thehigh capacity material and the polishing material are configured inserial flow orientation to each other where the polishing material isdownstream from the high capacity material.

Activated carbon is a fine-grained carbon with an extremely largesurface area and a highly porous structure. Its adsorption capacity istherefore especially high and is especially pronounced for hydrocarbonsin particular. Activated carbon consists primarily of carbon(mostly >90%) with a strongly porous structure. In addition, theinternal surface area of the activated carbon is between 500 and 2000m²/g carbon, which explains the high adsorption capacity of theactivated carbon.

A “high capacity” activated carbon is a material that has a loading atsaturation (q_(sat)) of at least 25% or at least 50% or at least 75%greater than a control sample of activated carbon (referred to herein aspolishing hydrocarbon absorbing material). Generally, the high capacityhydrocarbon absorber material has a greater saturation capacity(q_(sat)) than the polishing hydrocarbon absorber material.

In some embodiments the high capacity hydrocarbon absorbing polymericmaterial includes hydrocarbon absorbing polymeric polyethylene,polypropylene, polyurethane, polyester, and combinations thereof. Theseabsorbing polymeric materials can be in the form of a non-woven fabriclayer, nanofiber layer, a sponge or polymer foam element or layer. Inother embodiments the high capacity hydrocarbon absorbing material is anactivated carbon. In some embodiments, the high capacity hydrocarbonabsorbing material includes both a high capacity hydrocarbon absorbingpolymeric material and a high capacity hydrocarbon absorbing activatedcarbon material.

The high capacity hydrocarbon absorbing material includes one or more ortwo or more different types or kinds of high capacity hydrocarbonabsorbing material. The two or more high capacity hydrocarbon absorbingmaterials may be mixed together within a single volume or separated fromeach other by a divider or spacer element where they are in serial floworientation to each other.

In some embodiments the high capacity hydrocarbon absorbing materialincludes two or more high capacity hydrocarbon absorbing activatedcarbon materials. The two or more high capacity hydrocarbon absorbingactivated carbon material may be mixed together within a single volumeor separated from each other by a divider or spacer element where theyare in serial flow orientation to each other.

In some embodiments the high capacity hydrocarbon absorbing materialincludes two or more high capacity hydrocarbon absorbing polymericmaterials. The two or more high capacity hydrocarbon absorbing polymericmaterials may be mixed together within a single volume or separated fromeach other by a divider or spacer element where they are in serial floworientation to each other.

In some embodiments the high capacity hydrocarbon absorbing materialincludes a high capacity hydrocarbon absorbing polymeric material and ahigh capacity hydrocarbon absorbing activated carbon material. The highcapacity hydrocarbon absorbing polymeric material and the high capacityhydrocarbon absorbing activated carbon material may be mixed togetherwithin a single volume or separated from each other by a divider orspacer element where they are in serial flow orientation to each other.In these embodiments, the high capacity hydrocarbon absorbing polymericmaterial may represent from 10 to 90 wt % of the total high capacityhydrocarbon absorbing material and a high capacity hydrocarbon absorbingactivated carbon material may represent from 90 to 10% of the total highcapacity hydrocarbon absorbing material. The high capacity hydrocarbonabsorbing polymeric material may represent from 25 to 50 wt % of thetotal high capacity hydrocarbon absorbing material and a high capacityhydrocarbon absorbing activated carbon material may represent from 75 to50% of the total high capacity hydrocarbon absorbing material. The highcapacity hydrocarbon absorbing polymeric material may represent from 75to 50 wt % of the total high capacity hydrocarbon absorbing material anda high capacity hydrocarbon absorbing activated carbon material mayrepresent from 25 to 50% of the total high capacity hydrocarbonabsorbing material.

In many embodiments the polishing hydrocarbon absorber material is anactivated carbon. In some embodiments the polishing hydrocarbonabsorbing material includes two or more polishing hydrocarbon absorbingactivated carbon materials. The two or more polishing hydrocarbonabsorbing activated carbon material may be mixed together within asingle volume or separated from each other by a divider or spacerelement where they are in serial flow orientation to each other.

It is understood that the high capacity hydrocarbon absorbing materialand the polishing hydrocarbon absorber material are different materials.For example both the hydrocarbon absorbing material and the hydrocarbonabsorber material can be activated carbon, however, they are differenttypes of activated carbon that have different absorption properties.Generally, the polishing activated carbon has a greater loading orpolishing capacity (q_(t)) than the high capacity hydrocarbon absorbermaterial.

In some embodiments the hydrocarbon-in-water purification system hasabout an equal weight or volume amount of high capacity hydrocarbonabsorber material as compared to polishing hydrocarbon absorbermaterial. The high capacity hydrocarbon absorber material representsfrom 45 to 55 wt % of the total absorber material (contained within thehydrocarbon-in-water purification system) and the polishing hydrocarbonabsorber material is about 55% to 45% of the total absorber material.

In some embodiments having a greater wt % of high capacity hydrocarbonabsorber material as compared to polishing hydrocarbon absorber materialhas been shown to improve the lifetime of the overall hydrocarbon inwater purification system. In some of these embodiments the highcapacity hydrocarbon absorber material represents from 55% to 95% wt ofthe total absorber material and the polishing hydrocarbon absorbermaterial is about 45% to 5% of the total absorber material.

In other embodiments having a greater wt % of polishing hydrocarbonabsorber material as compared to high capacity hydrocarbon absorbermaterial has been shown to improve the lifetime of the overallhydrocarbon in water purification system. In some of these embodimentsthe high capacity hydrocarbon absorber material represents from 15% to45% wt of the total absorber material and the polishing hydrocarbonabsorber material is about 85% to 55% wt of the total absorber material.

In some embodiments the hydrocarbon-in-water purification system hasabout ⅔ high capacity hydrocarbon absorber material and ⅓ polishinghydrocarbon absorber material. The high capacity hydrocarbon absorbermaterial represents from 60 to 75 wt % of the total absorber material(contained within the hydrocarbon-in-water purification system) and thepolishing hydrocarbon absorber material is about 40% to 25% of the totalabsorber material.

As used herein, terms such as “inside”, “outside”, “vertical”,“horizontal”, “above”, “below”, “left”, “right”, “upper” and “lower”,“clockwise” and “counter clockwise” and other similar terms, refer torelative positions as shown in the figures. In general, a physicalembodiment can have a different orientation, and in that case, the termsare intended to refer to relative positions modified to the actualorientation of the device.

FIG. 4 is a schematic diagram view of an engine system 150 showingvarious components that can be used to provide and control fluid flowfrom a source of fuel having a potential need for fuel water separation.As shown, the engine system 150 includes a fuel source 152, fuel waterseparator 154, a water filter 156, a fuel pump 158, an engine 160, acontroller 162, a fuel line 164, and a water line 166. A fuel line valve170, a water line valve 172, a water-in-fuel (WIF) sensor 174, atemperature sensor 176, are also included in this illustrated embodimentof the engine system 150.

Although these components are included in the illustrated embodiment, itshould be understood that the disclosure is not limited to includingeach component shown, and furthermore, other components may be includedthat are not shown or may be found in other arrangements that may alsobe used with control techniques described herein for separating waterfrom fuel and purifying the separated water to remove hydrocarbons. Forexample, the engine system 150 may also be configured as described inEuropean Patent Application 2,878,352, filed 29 Nov. 2013, and titled“Fuel Filter Assembly, Filter Element and Method for Draining Water froma Fuel Filter Assembly,” which is incorporated herein for all purposes.

During operation, the engine system 150 may separate water from fuel.Water may be present in the fuel, for example, due to atmosphericcondensation or non-ideal fuel management. In some cases, fuel in thefuel source 152 may be mixed with water. The engine system 150preferably removes water from the fuel before it reaches the engine 160.

The water in the engine system 150 may not be useful, however, and invarious embodiments, the water is preferably evacuated out of the enginesystem 150, which may enter into the environment 180. In at least oneembodiment, water may evaporate into the environment 180.

The separated water may be unclean, however. As used herein, “uncleanwater” means water that may contain or is considered to containcontaminants, such as hydrocarbons. Accordingly, “clean water” meanswater that does not have contaminants or is considered to besufficiently free of contaminants. Preventing the release of uncleanwater into the environment 180 may be preferable, for example, to complywith jurisdictional requirements. In various embodiments, a thresholdlevel of contaminants may be determined in response to jurisdictionalrequirements. In many cases, “unclean water” is preferably purified into“clean water” that may enter into the environment 180 in compliance withjurisdictional requirements.

In various illustrative embodiments, the engine system 150 preferablypurifies the unclean water separated before leaving the engine system150. The various components of the engine system 150 and theiroperations related to purifying unclean water are described herein infurther detail.

The fuel source 152 may be a fuel tank capable of containing andproviding a fuel to the engine 160 through fuel line 164. The engine 160may be an internal combustion engine, for example, which combusts thefuel (for example, diesel) to provide mechanical energy (for example,torque for automotive power) during normal operation. During normaloperation of the engine 160, the fuel line 164 is typically in fluidcommunication with the fuel source 152, the fuel water separator 174,the fuel pump 158, and the engine 160.

Fluid communication along the fuel line 164 may be interrupted by thefuel line valve 170, which can be open or closed. A closed fuel linevalve 170 preferably prevents fluid communication across the valve ineither direction. In at least the illustrated embodiment, the fuel linevalve 170 is positioned between the fuel source 152 and the fuel waterseparator 154 along the fuel line 164. During normal operation of theengine 160, the fuel line valve 170 is preferably open.

Fuel is preferably drawn by the fuel pump 158 upstream or downstreamalong the fuel line 164. As used herein to describe the engine system150, the term “upstream” along the fuel line 164 means a directiontoward the fuel source 152. Accordingly, the opposite term “downstream”along the fuel line 164 means a direction toward the engine 160.

The fuel pump 158 may provide a pressure differential along the fuelline 164. During normal operation, the fuel pump 158 provides arelatively higher pressure downstream (+) and a relatively lowerpressure upstream (−) to draw fuel downstream.

In some embodiments, the fuel pump 158 may operate in reverse. Forexample, the fuel pump 158 may provide a relatively lower pressureupstream and a relatively higher pressure upstream to draw fuelupstream.

The fuel water separator 154 preferably removes a sufficient amount ofwater from the fuel to prevent or mitigate harm to the engine 160. Asshown, the fuel water separator 154 is positioned downstream of the fuelsource 152 and upstream of the fuel pump 158 and the engine 160.

In many embodiments, the fuel water separator 154 is similar to fuelfilter element 50 in FIG. 2. In various illustrative embodiments, thefuel water separator 154 receives fuel mixed with water in an upstreaminlet, filters water from the fuel, provides the filtered fuel to adownstream outlet to the fuel line 164, and provides water to the waterline 166.

The water line 166 may provide fluid communication between theenvironment 180 and the fuel water separator 154. In the illustratedembodiment, the water line 166 typically provides fluid communicationamong the fuel water separator 154, the water filter 156, and theenvironment 180. As shown, the water filter 156 is positioned downstreamof the fuel water separator 154 and upstream of the environment 180.

As used herein, “upstream” along the water line 166 means a directiontoward to the fuel water separator 154. Accordingly, the opposite term“downstream” along the water line 166 means a direction toward theenvironment 180.

In many embodiments, the water provided from the fuel water separator154 to the water line 166 is considered unclean water and may include ahydrocarbon-in-water dispersion. Unclean water is preferably purified bythe water filter 156 to provide clean water to the environment 180. Forexample, the water filter 156 may include the hydrocarbon-in-waterpurification system 10, 100 of FIG. 1 or 3, which absorbs hydrocarbonsinto a hydrocarbon absorbing material to purify water.

Fluid communication along the water line 166 may be restricted by thewater line valve 172, which may allow fluid to flow in only onedirection along the water line 166. For example, the water line valve172 may be a check valve, which may be pressure sensitive to open andallow flow in one direction and to close and prevent fluid flow in theother direction. In at least one embodiment, the water line valve 172 isa passive check valve. In the illustrated embodiment, the water linevalve 172 is positioned along the water line 166 between the fuel waterseparator 154 and the water filter 156.

During normal operation, the fuel pump 158 may create a lower upstreampressure than the pressure of the environment 180 (for example,atmospheric pressure), which may cause a pressure differential acrossthe water line valve 172 that is lower upstream (−) and higherdownstream (+) along the water line 166. In the illustrated embodiment,the water line valve 172 tends to close in response this pressuredifferential and prevents fluid from flowing upstream along the waterline 166.

Water is preferably evacuated from the engine system 150 by flowingwater downstream through water line valve 172. The separated water mayflow from the fuel water separator 154, through to the water filter 156,and out of the engine system 150, in some embodiments, via a pressuredifferential. For example, water may be evacuated by building asufficient pressure differential builds across the water line valve 172,particularly a higher pressure upstream than downstream, to open it andallow water to flow downstream along the water line 166 to evacuatewater. In many embodiments, the water line valve 172 preferably allowsfluid to flow only downstream along the water line 166.

In the illustrated embodiment, the fuel pump 158 may be used to providethe pressure differential needed to evacuate water. For example, thefuel pump 158 can operate in reverse to create a higher upstreampressure than the pressure of the environment 180, which is sufficientto open the water line valve 172. In particular, the fuel line valve 170may also be closed to facilitate the build-up of pressure in the fuelwater separator 154, for example, by preventing fuel pumped upstreamfrom flowing back into the fuel source 152. Once opened due to asufficient pressure differential, the open water line valve 172 allowsfluid to flow downstream along the water line 166 across the pressuredifferential toward the environment 180.

In many embodiments, the engine 160 is preferably not operating (forexample, not consuming fuel) while the fuel pump 158 is reversed.Accordingly, the engine 160 may preferably be turned off beforeevacuating water. In other embodiments, however, another component otherthan the fuel pump 158 may be used to provide pressure to evacuatewater, or a different valve other than a check valve, such as an activeone-way valve that is not necessarily responsive to pressure in the fuelline 164, may be used to allow water to flow downstream for evacuation.

In various embodiments, the unclean water (for example,hydrocarbon-in-water dispersion) may be described as being separated ina continuous manner by the fuel water separator 154 as fuel flowsthrough it. When an engine 160 is running, an amount of water separatedmay be modeled and estimated in response to one or more parameters.Non-limiting examples of water separation parameters include: the typeof filter material in the fuel water separator 154, the “saturation” ofsuch filter material (for example, the amount of filter loading), theconcentration of water in the fuel, the temperature of the fuel, and theflow rate of fuel, among others.

While the engine 160 is running, however, the fuel pump 158 ispreferably in normal operation and water is not being evacuated. It maybe beneficial to collect and store the water until it can be evacuated.Accordingly, the unclean water may be described as being evacuated fromthe fuel water separator 154 in batches. The process of continuouslyseparating water and evacuating it in batches may be described as a“multi-batch” process. In some illustrative embodiments, the fuel waterseparator 154 includes a reservoir for collecting the unclean wateruntil it is evacuated into the water filter 156.

In many illustrative embodiments, the unclean water preferably ispurified while residing in the water filter 156. A required or minimumamount of time in the water filter 156 to sufficiently purify theunclean water for evacuation from the engine system 150 may be modeledor estimated in response to one or more parameters. For example, thewater purification parameters may include the kinetic parameters, suchas adsorbent loading, ratio of adsorbate to adsorbent, equilibriumadsorbate concentration, adsorbate characteristics, adsorbentcharacteristics (for example, physical characteristics such as surfacearea), and temperature. In many embodiments, a kinetic profile based ona particular set of kinetic parameters that models the concentration ofhydrocarbons in water versus the amount time in the water filter 156 maybe used to determine a residence time threshold, as well as otheraspects of the control technique, as described herein elsewhere.

In many embodiments, it may be preferable to maximize or optimize theamount of time unclean water spends in the water filter 156, which maybe evacuated in batches out of the fuel water separator 154 and into thewater filter 156. On the other hand, it may also be preferable tominimize or optimize the frequency that the engine system 150 is turnedoff for evacuating water from the fuel water separator 154 (in otherwords, minimizing the interruption of operating time). The techniquedescribed herein defines a technique for optimizing the purification andthe evacuation of water that may be used with engine system 150.

In many illustrative embodiments, the engine system 150 evacuates apredetermined water volume from the fuel water separator 154 and intothe water filter 156. The water filter 156 is preferably designed forreceiving and storing a target number of predetermined water volumes(for example, one, two, three, or more). The target number ofpredetermined water volumes may be selected to facilitate enoughresidence time of the water in the water filter 156 based on anestimated water separation rate in the fuel water separator 154according to a particular application.

In one illustrative automotive application, for example, the estimatedrate of water separation by the fuel water separator 154 may bedetermined to be about 40 mL per hour of engine operation under typicalconditions. In the same engine system 150, the estimated rate of waterpurification by the water filter 156 may be determined to be about 40 mLper hour of residence time under typical conditions. Furthermore, thepredetermined water volume for evacuation may be about 40 mL by design,which means three water volumes would be evacuated over a 3 hour period(for example, entering into the water filter at the 0, 1, and 2 hourmarks). To facilitate the desired residence time in the water filter 156for all three water volumes, the water filter 156 may be designed tostore multiple predetermined water volumes (for example, at leastthree). By the time of a fourth evacuation at the 3 hour mark, the firstwater volume will have at least 3 hours of residence time in the waterfilter 156 and may be considered to be clean for evacuation out of thewater filter 156.

The water filter 156 may be designed to receive and evacuate thepredetermined water volumes according to a first-in, first-out process(FIFO). A FIFO process preferably maximizes the amount of time a watervolume resides in a water filter 156 capable of containing multiplewater volumes by evacuating water that has spent the most time in thewater filter 156 from the engine system 150. In the illustrativeautomotive application described, for example, the first 40 mL watervolume evacuated into the water filter 156 at the 0 hour mark may residein the water filter 156 for 3 hours and be evacuated from the waterfilter 156 before the second and third water volumes (for example, atthe 3 hour mark when a fourth water volume is evacuated into the waterfilter 156).

The engine system 150 may include a control system for managing the flowof fuel and water through the water filter 156. In the illustratedembodiment, the control system includes the controller 162 in operativecommunication with various components in the engine system 150 to manageand control, in particular, the evacuation of water. In manyillustrative embodiments, the controller 162 also tracks the residencetime of unclean water in the water filter 156 to facilitate themanagement of water evacuation. The controller 162 may be configured toimplement various illustrative methods to manage and control waterevacuation described herein elsewhere.

Many aspects of this disclosure are described in terms of receivers,timers, managers, operators, or controllers that include sequences ofactions to be performed by components of a control and/or acommunication system, which can be a computer system or other hardwarecapable of executing programmed instructions. These components can beembodied in a controller of an engine system (for example, an enginecontrol module/unit (ECM/ECU)), multiple controllers, or a controllerseparate from the engine system communicating with the enginecontroller. In at least one embodiment, depicted and describedcomponents can be part of a wired or wireless network, such as acontroller area network (CAN), in which the controller, sensor,actuators communicate via digital messages. It will be recognized thatin embodiments consistent with the present disclosure, each of thevarious actions could be performed by specialized circuits (for example,discrete logic gates interconnected to perform a specialized function),by program instructions being executed by one or more processors (forexample, a central processing unit (CPU) or microprocessor), or by acombination, all of which can be implemented in the controller 162and/or another controller(s). A controller may utilize a processor orshare a processor with another component to perform actions required.Logic of embodiments consistent with the disclosure can be implementedin any suitable data processor, which may be configured to executeinstructions on a computer readable medium. A computer readable mediummay include tangible forms of media, for example, a random access memory(RAM), a read-only memory (ROM), an erasable programmable read-onlymemory (for example, EPROM, EEPROM, or Flash memory), an optical fiber,and a portable compact disc read-only memory (CD-ROM), or any othersolid-state, magnetic, and/or optical disk medium capable of storinginformation. Thus, various aspects can be embodied in many differentforms, and all such forms are contemplated to be consistent with thisdisclosure.

The controller 162 may be in operative communication with the fuel linevalve 170 and the fuel pump 158. In many illustrative embodiments, thecontroller 162 provides signals to command the fuel pump 158 to operatenormally and to operate in reverse. Further, the controller 162 mayprovide signals to command the fuel line valve 170 to open or to close.In this manner, the controller 162 is configured to control theevacuation of water.

Also, the controller 162 may be in operative communication with sensorsto receive sensor data. In some illustrative embodiments, the controller162 is operatively coupled to the WIF sensor 174 and the temperaturesensor 176 to receive various sensor signals representing sensor data.The controller 162 may use sensor data may to facilitate the managementof water evacuation.

The WIF sensor 174 preferably provides a signal indicating that thepredetermined water volume is ready to evacuate from the fuel waterseparator 154. In various illustrative embodiments, the WIF sensor 174may be in fluid communication with the water collection reservoir of thefuel water separator 154 and positioned to be triggered when the waterlevel (for example, fuel-water interface) in the reservoir meets orexceeds a predetermined trigger volume.

In many embodiments, the predetermined trigger volume is preferablyrelated to the predetermined water volume by a safety factor to preventseparated fuel from flowing into the water filter 156. For example, theWIF sensor 174 position may trigger when at least 50 mL of water hasbeen collected in the fuel water separator 154 and only 40 mL of watermay be evacuated into the water filter 156.

In various embodiments, one WIF sensor 174 is included. However, two ormore WIF sensors 174 may be included in various embodiments.

In some illustrative embodiments, the controller 162 controls evacuationby commanding the fuel pump 158 to reverse for a predetermined amount oftime in response to the WIF sensor 174 being triggered (for example, andthe engine 160 being off). In at least one embodiment, the controller162 reverses the fuel pump 158 for a predetermined amount of timeestimated to evacuate the predetermined amount of water under typicaloperating conditions.

The temperature sensor 176 preferably provides a signal indicating atemperature along the water line. The water temperature may affect theability of the water to be evacuated from the engine system 150. Forexample, the temperature sensor 176 may provide a low-temperature signalindicating a possible build-up of ice that may restrict the flow ofwater. The water temperature may also affect the kinetics of the waterfilter 156, or its capacity to filter hydrocarbons from water. Inresponse to receiving the low-temperature signal, the controller 162 mayupdate a fault state to indicate that water should not be evacuateduntil a later time, for example, to facilitate water evacuationmanagement.

The temperature sensor 176 may be dedicated for indicating watertemperature or may be a temperature sensor typically present in theengine system 150 for indicating other temperatures. In manyillustrative embodiments, the water line 166 is positioned in closeproximity to the engine 160 such that the temperature of the water inthe water line 166 is within 5 degrees Celsius of the engine 160. Insuch embodiments, a dedicated sensor for water temperature may not beneeded. For example, the temperature sensor 176 may be the engine blocksensor, which may already be used to provide the engine blocktemperature, for example, to an ECU. In such cases, the controller 176may receive the signal indicating the temperature along the water linefrom the ECU. This configuration has the further benefit of normalizingthe temperature of the water line 166 to about the engine blocktemperature, which may prevent freezing and ice-buildup when warmed up.

Referring now to FIGS. 4 and 5 together, a schematic diagram view of anillustrative process 200 for managing the evacuation of water is shown.The process 200 may be implemented in controller 162, for example.

In step 202, an indication that water is ready to evacuate isdetermined. The indication may be determined in response to a WIF sensor172 being triggered indicating a predetermined water volume is ready toevacuate from the fuel water separator 154. In such embodiments, theengine system 150 operator may also be notified (for example, by lightlamp in instrument cluster) that the WIF sensor 172 has been triggered.

In step 204, water evacuation conditions are checked. In variousembodiments, an engine operation state is checked. For example, if theengine key is in the “off” position, the engine 160 is determined to benot operating (for example, in an off state and not running). In someillustrative embodiments, the water evacuation conditions are checked inresponse to the engine key being turned to the “off” position.

On the other hand, if the engine key is in the “on” position, indicatingthat the engine 160 is operating, a timer may be started. After apredetermined duration, the timer may expire indicating that the WIFsensor 174 has been triggered for the predetermined duration. Thepredetermined duration may correspond to an estimated amount of waterseparated by the fuel water separator 154 over the predeterminedduration that exceeds the size of the water collection reservoir and/orexceeds the capacity of the water filter 156 to purify within aparticular time limit.

The operator of the engine system 150 may be notified that water must beevacuated within a particular period of time, and a second timer may bestarted. Upon expiration of the second timer, the engine system 150 maytake severe measures to preserve the ability of the water filter 156 tosufficiently purify the water until the operator turns off the engine160 (for example, pulls over) so that water can be evacuated.Non-limiting examples of severe measures include: derating the engineoutput, flashing the instrument lamp, and activating an audible alarm.

In further embodiments, a water temperature is checked prior toevacuation. If the water temperature is determined to be below athreshold level, then water may not be evacuated to the potential offreezing water. For example, if the temperature sensor 176 indicates alow water temperature (for example, less than 10 degrees Celsius), thewater may not be evacuated.

In additional embodiments, the purification progress of the water volumeto be evacuated from the water filter 156 is checked. If the watervolume to be evacuated is determined to be not clean, then the water maynot be evacuated from the water filter 156. The purification of thewater volume is preferably tracked from the entry of the water volumeinto the water filter 156 until the water volume is evacuated from thewater filter 156 to facilitate this determination.

In step 206, water is evacuated from the fuel water separator 154 intothe water filter 156 if the evacuation conditions are satisfactory. Ifthe water filter 156 is filled with water before the evacuation, anolder water volume may be evacuated from the water filter 156.

In step 208, parameters indicating the state of the filter are updated.For example, fault states may be determined and set. Non-limitingexamples of fault states include a low temperature fault, an excessrestriction fault, a valve failure fault, an excess water fault, and afilter expired fault. The fault states preferably indicate that theevacuation attempt failed and that water was not evacuated. The absenceof any fault states indicates that the evacuation was successful. Theengine operator may be notified accordingly.

In one example, a low temperature fault may be determined and set inresponse to a low temperature signal from the temperature sensor 176,which may impact the ability to evacuate water due to freezing water. Ina second example, an excess restriction fault may be determined and setin response to an excessive variation in fuel pump characteristicsduring reverse operation (for example, during evacuation), which mayimpact the ability to evacuate water due to a potential restricted flow.In a third example, a valve failure fault may be determined and set inresponse to an excessive variation in fuel pump characteristics duringoperation in reverse (for example, during evacuation, the fuel linevalve 170 not being closed or water line valve 172 not opening), whichmay impact the ability to evacuate water due to the undesirable loss ofpressure or build-up of pressure. In a fourth example, an excess waterfault may be determined and set in response to water collected by thefuel water separator 154 exceeding the capability of the water filter156 to purify within a particular time limit, which may result inundesirable evacuation of unclean water. In a fifth example, a filterexpired fault may be determined and set in response to the water filter156 or a purification bed 300 reaching the end of a useful service life,which may result in insufficient purification of unclean water despiteresidence time. In at least one embodiment, the filter expired fault isdetermined in response to the final purification bed 300 reaching theend of its useful service life (for example, its bed loading threshold).

FIG. 6 is a schematic diagram view of the illustrative fuel waterseparator 154 and the illustrative water filter 156. In the illustratedembodiment, the fuel water separator 154 removes water 192 from the fuel190. The separated fuel 190 may continue downstream in normal operation.The separated water 192 may collect in a water collection reservoir 194,preferably at the bottom of the fuel water separator 154.

In some illustrative embodiments, the fuel 190 and the water 192 mayreside in the same volume after separation. The separated fuel 190 mayfloat above the separated water 192 as a separate phase, for example.The water collection reservoir 194 may be defined as a lower portion ofa volume in the fuel water separator 154. Although the water collectionreservoir 194 is schematically shown as a cylinder, any suitable shapecapable of separating and containing water and fuel is contemplatedwithin this disclosure.

Also, as shown, the WIF sensor 174 is positioned in the water collectionreservoir 194. The WIF sensor 174 may be triggered in response todetecting when the level of the water 192 has reached a predeterminedwater volume. The trigger preferably indicates that a water volume isready to be evacuated. When evacuated, a water volume preferably exitsthe fuel water separator 154, crosses the water line valve 172, andenters into the water filter 156. In many illustrative embodiments, thewater volume may be related to the predetermined water volume by asafety factor. For example, the predetermined water volume may be 50 mLand the water volume to be evacuated may be 40 mL.

The water filter 156 includes an inlet 196 and an outlet 198. The waterfilter 156 is preferably designed to evacuate the first or oldest watervolume out of the outlet 198 when a new water volume enters the inlet196. For example, when the water filter 196 is first installed, thereare no water volumes in the water filter 196, and upon a firstevacuation, a first water volume preferably equal to the predeterminedwater volume enters the water filter 156. Then, additional evacuationsraise the water level in the filter 156, preferably in increments of thepredetermined water volume. As schematically shown, the inlet 196 ispositioned adjacent the bottom of the water filter 156 and the outlet198 is positioned adjacent the top, or at the opposite end, of the waterfilter 156. Preferably, only purified, clean water exits, or evacuates,from the outlet 198.

In many embodiments, the water filter 156 includes one or morehydrocarbon absorbers. The hydrocarbon absorbers preferably include thehydrocarbon absorber material described in the hydrocarbon-in-waterpurification systems 10, 100. The water filter 156 may include one ormore types of hydrocarbon absorber materials. Stages may be defined bythe water filter 156 according to the type of material. In at least oneembodiment, two hydrocarbon absorber materials are utilized, such as ahigh capacity material and a polishing material, which respectivelydefine a high capacity stage and a polishing stage.

Models may be generated that predict the behavior of hydrocarbon removalas water advances through the water filter 156, for example, byconsidering the total volume of the water filter 156 as a plurality ofdiscrete purification beds 300 (for example, bins, stages, or zones).Water volumes can “enter” and “exit” a purification bed 300. Such modelsmay presume that, as a new water volume enters the water filter 156,existing water volumes in the water filter 156 are displaced upward andthat each water volume does not substantially mix with other watervolumes as they advance through the water filter 156.

In many illustrative embodiments, each purification bed 300 preferablyis defined to have a void volume equal to the predetermined watervolume. For example, the total volume of the purification bed 300 may beabout 75 mL with a void volume of about 40 mL and about 35 mL forabsorbing material. In other words, water may be estimated by the modelas advancing through the water filter 156 in discrete volumes in singlefile; each discrete volume residing in a discrete purification bed 300;and each new water volume displacing the existing water volumes upwardby one purification bed 300.

Although any number of purification beds 300 may be defined, in theillustrated embodiment, the water filter 156 includes eight purificationbeds 301, 302, 303, 304, 305, 306, 307, 308 arranged from a firstpurification bed 301 to a final purification bed 308. Each purificationbed 300 may be defined as upstream or downstream from anotherpurification bed 300 along the water line 166.

The purification beds 300 may include a particular absorption materialor a particular absorption stage. Furthermore, each purification bed 300may correspond with a particular absorber, absorber material, orabsorption stage. For example, in at least some embodiments, the lastpurification bed 308 corresponds to a polishing absorption stageincluding one polishing absorber made of a polishing material. Also, inat least one embodiment, the purification beds 301 to 307 correspond toone high capacity absorption stage having one high capacity absorbermade of a high capacity material.

Each purification bed 300 may be considered to have a corresponding orassociated bed loading state representing the ability of thepurification bed 300 to absorb hydrocarbons from water, for example. Forexample, the bed loading state may increment if a water volume is fullyor partially cleaned in the purification bed 300. Once a purificationbed 300 absorbs enough hydrocarbons, the purification bed 300 may beconsidered to have reached the end of its useful life, which may bedefined by the adsorption isotherm model. Accordingly, a bed loadingthreshold for a purification bed 300 may be determined in response tothe adsorption isotherm model. The bed loading state may be set to“threshold reached” or “ineffective” to indicate that the purificationbed 300 can no longer effectively absorb hydrocarbons from uncleanwater. Conversely, a bed loading state of “threshold not reached” or“effective” may indicate that the purification bed 300 can continue toabsorb hydrocarbons and impact the purification of unclean water.

The bed loading threshold may be different for each purification bed 300according to the adsorption isotherm model. In one example, thematerial, size, shape, and other characteristics of a hydrocarbonabsorber may impact its capacity to absorb hydrocarbons over its usefulservice life, and the bed loading threshold may be adjusted accordingly.For example, a high capacity purification bed may have a bed loadingthreshold of 100, whereas a polishing purification bed may have a bedloading threshold of 10.

Furthermore, the position of the purification bed 300 in the waterfilter 156 may impact the bed loading threshold. The bed loading statesare set based on modeling the multi-batch process using an adsorptionisotherm model. In at least one embodiment, the bed loading threshold ofthe purification beds 300 may decrease in a downstream direction,recognizing that upstream purification beds 300 will absorb morehydrocarbons earlier in the useful life of the water filter 156. Forexample, the bed loading thresholds may be set at 100 for the firstpurification bed 301, 95 for the second purification bed 302, 85 for thethird purification bed 303, and so on, 10 for the final purification bed308 (for example, the final purification bed can clean 10 unclean watervolumes before reaching the bed loading threshold).

Each water volume within each purification bed 300 may also beconsidered to have an associated purification state representing the howmuch the water volume has been purified. In many embodiments, new watervolumes entering the water filter 156 are considered to be uncleanwater. Accordingly, the purification state of new water volumes areinitialized or set to “unclean.” However, once a water volume hasresided in one or more effective purification beds 300 for the residencetime threshold, the water may be considered to be clean water.Accordingly, the purification state may be set to “clean” to indicatethat the water volume includes “clean water,” which may be evacuatedfrom the water filter 156. Conversely, as long as the water volume isconsidered to include “unclean water,” the purification state may remainas “unclean.”

The purification beds 300 may be arranged in any suitable manner in thewater filter 156 to facilitate a FIFO process. In many embodiments, thefirst purification bed 301 is defined as downstream of the inlet 196 andupstream of all other purification beds 302 to 308. For example, waterentering into the water filter 156 may enter into the first purificationbed 301 before any other purification bed.

In various embodiments, the last purification bed 308 is defined asupstream of the outlet 198 and downstream of all other purification beds301 to 307. For example, water exiting the water filter 156 may leavefrom the final purification bed 308 instead of any other purificationbed.

In the illustrated embodiment, when the water 192 is introduced into thewater filter 156, the water passes through the first purification bed301, then the second purification bed 302, then the third purificationbed 303, and so on until the water passes through the final purificationbed 308 and exits the water filter through outlet 198.

In at least one embodiment, the purification beds 300 are arrangedlinearly along an axis defined along the height of the water filter 156.For example, the purification beds 300 may be defined as “stacked” alongthe height of the water filter 156. The shapes and sizes of thepurification beds 300 may also be defined in any other suitable manner,including a concentric or nested manner, similar the absorber material36, 46 shown in FIG. 3.

FIG. 7 is a schematic diagram view of the illustrative controller 162.As illustrated, the controller 162 is coupled to the WIF sensor 174 andthe temperature sensor 176 to receive sensor data. The sensor data mayindicate that a new water volume is ready to evacuate from a watercollection reservoir, for example. A sensor data receiver 400 maydetermine one or more parameters in response to the sensor data, such asthe water in fuel parameter 404 and the water temperature parameter 422.

The controller 162 is also shown coupled to the fuel line valve 170 andthe fuel pump 158 to control water evacuation. In many illustrativeembodiments, the controller 162 is operable to determine, to provide,and to store one or more parameters related to water evacuationmanagement and control. As used herein, determining data may alsoinclude receiving data into the controller 162.

In at least some embodiments, the controller 162 includes a water filtermanager 401 configured to determine various parameters, thresholds, andstates to manage the evacuation of water. In various embodiments, thewater filter manager 401 also includes a purification bed tracker or awater volume tracker to facilitate management of water evacuation. Forexample, a purification bed tracker may maintain and update a bedloading state 416 for each purification bed based on its associatedkinetic model. In another example, a water volume tracker may maintainand update a purification state 410 for each water volume based on theassociated kinetic model of a current purification bed. The type oftracker may be selected, for example, based on resources available inthe processing or memory of the controller 162.

Further, in various embodiments, the controller 162 includes anevacuation operator 403 configured to provide one or more commands orstates, such as alarm commands 408, fault states 420, and waterevacuation command 420. For example, a fault state 420 may be providedto an ECU external to the controller 162. Commands and states may berepresented by signals.

In at least one embodiment, the controller 162 is configured todetermine an engine key parameter 402 indicating whether the engine keyis turned to an “on” or “off” position. The controller 162 is alsopreferably configured to determine a water in fuel parameter 404indicating whether a WIF sensor 174 is trigger or not triggered by thepresence of a predetermined volume of water.

As illustrated, controller 162 is further configured to maintain a timer406, which may track one or more periods of time that have elapsed. Adifferent timer 406 may be maintained for each period of time beingtracked. In some embodiments, a timer 406 may track a period of timethat has elapsed since the WIF sensor has been triggered. In variousembodiments, a timer 406 may track a residence time for a water volume,which may be defined as the period of time that the water volume hasspent in one or more effective purification beds. A timer 406 may beupdated in any suitable time increments, on the order of seconds,minutes, or hours, for example.

Still further, the illustrated controller 162 is configured to provideone or more alarm commands 408 in response to the expiration of thetimer 406. The alarm commands 408 may warn an engine operator or takeaction to preserve the ability of the engine system to evacuatesufficiently purify water.

In various embodiments, the controller 162 is configured to determineone or more purification states 410 of one or more water volumes inresponse to one or more residence times 412 and one or more residencetime thresholds 414. For example, a purification state 410 may be set tounclean until a residence time 412 meets or exceeds a residence timethreshold 414 for the water volume. The purification state 410 may thenbe set to clean.

In further embodiments, the controller 162 is configured to determineone or more bed loading states 416 and one or more bed loadingthresholds 418 for one or more purification beds. The controller 162 maycompare the bed loading states 416 to associated bed loading thresholds418. Once one or more bed loading states 416 reach associated bedloading thresholds 418, a fault state 420 may be updated to indicate anexpired filter.

In many embodiments, the controller 162 is configured to determine awater temperature parameter 422 indicating the water temperature at thetemperature sensor 176. The controller 162 may also determine a lowtemperature threshold 424 for comparison with the water temperatureparameter 422. In response to the water temperature parameter 422dropping below the low temperature threshold 424, the controller 162 mayupdate a fault state 420 to indicate a low temperature.

In at least some illustrative embodiments, the controller 162 maydetermine a water evacuation command 426 in response to the engine keyparameter 402 indicating an “off” position, the water in fuel parameter404 indicating a triggered WIF sensor, the fault state 420 notindicating a lower temperature (or other faults), and a purificationstate 410 associated with the next dischargeable water volume in thewater filter being clean. In various illustrative embodiments,evacuation operator 403 provides the evacuation command 426 preferablyto close the fuel line valve 170 and to reverse the fuel pump 158.

Processes that may be implemented on the controller 162 are describedherein in more detail with respect to FIGS. 8, 9, 10, and 11.

FIG. 8 is a schematic diagram view of an illustrative process 202 forchecking water evacuation conditions. The process 202 begins withdetermining that a new water volume is ready to evacuate in step 501.Then, in step 502, whether a water temperature is below a lowtemperature threshold is determined. If the water temperature is belowthe low temperature threshold, the process 202 bypasses the step ofintroducing a new water volume (for example, evacuating a water volume)and continues on to step 503.

In step 503, a fault state is updated in response to one or moreconditions, such as a low temperature, an excess of water, and anexpired filter. Each of the conditions may indicate that the new watervolume cannot be evacuated, and thus an attempted evacuation has failed.

However, if in step 502, the water temperature is not below the lowtemperature threshold, the process 202 may continue onto step 504.

In many embodiments, the process 202 may be used with a water filterthat contains one or more water volumes and a plurality of purificationbeds arranged from a first purification bed to the final purificationbed such that the first purification bed receives new water introducedinto the water filter from a water collection reservoir and the finalpurification bed discharges water from the water filter. The one or morewater volumes preferably reside in the plurality of purification beds.

According to step 504, the purification state of the water volume in thefinal purification bed, which would be discharged if a new water volumewere introduced into the water filter, is determined. The purificationstate may be determined in response to tracking the residence time ofthe next dischargeable water volume in at least one of the purificationbeds.

In continuing onto step 505, whether the dischargeable water volume inthe final purification bed in the water filter is clean or not clean isdetermined, for example, in response to the purification statedetermined in step 504. If the dischargeable water volume is clean, theprocess 202 may continue onto step 506 to evacuate water from the watercollection reservoir to introduce a new water volume into the firstpurification bed of the water filter. On the other hand, if thedischargeable water volume is not clean, the process continues onto step507 to determine whether one or more purification beds have reachedassociated bed loading thresholds.

According to step 506, a new water volume is introduced into the firstpurification bed in response to determining that the dischargeable watervolume is clean. The new water volume, once introduced, moves each ofthe one or more water volumes in the water filter such that thedischargeable water volume leaves the final purification bed and a nextdischargeable water volume of the one or more water volumes enters thefinal purification bed.

On the other hand, in step 507, whether the bed loading state associatedwith at least one of the purification beds exceeds an associated bedloading threshold is determined. The bed loading state may be determinedin response to tracking the residence time of water in the at least onepurification bed, for example.

In various embodiments, a filter may be determined to be expired inresponse to determining that one or more purification beds have bedloading states that exceed their associated bed loading thresholds. Ifthe remaining effective purification beds in the water filter haveinsufficient capacity to clean one water volume, the water filter may beincapable of cleaning another water volume. The water filter may then bedeemed expired. In one example, the filter may be considered expired ifthe final purification bed has reached its associated bed loadingthreshold. In another example, the filter may be considered expired ifsome or all of the purification beds have reached their associated bedloading thresholds.

Continuing on from step 507, faults other than lower temperature, excesswater, or expired filter may be checked for in step 508, such asexcessive restrictions or a valve failure during evacuation. Then, instep 503, the fault states are updated and may be made available on acontroller, for example, for diagnosis.

After either step 506 or 503, the process 202 is then finished at step509. In this manner, water volumes that enter the water filter may beevaluated to facilitate only clean water being evacuated from the waterfilter.

FIG. 9 is a schematic diagram view showing an illustrative process 600for tracking a purification state (PS) and a bed loading state (LS) in apurification bed tracker, as water volumes advance through anillustrative water filter. In many embodiments, each purification bed inthe water filter may be associated with a different purification bedtracker and, at any given time, a different water volume.

In the illustrated embodiment, the purification bed tracker keeps trackof various water volumes Y that advance through purification bed X. Forexample, the process 600 may begin with a water evacuation in step 601,which can be initiated by a water evacuation command form anillustrative controller. This may cause a previous water volume Y−1 toexit purification bed X in a downstream direction and cause a watervolume Y to enter purification bed X from an upstream direction in step602.

In many illustrative embodiments, the purification bed tracker maintainsparameters, such as a current residence time of a current water volume Yresiding in the associated purification bed X, a current purificationstate of the current water volume Y, and a bed loading state of theassociated purification bed X. The parameters may be stored in a datastructure, such as a table, which may be updated by the process 600.

The process 600 may track the purification state of the water volume Yfrom 1 to 0 with PS=1 representing an unclean state and PS=0representing a clean state. In at least some illustrative embodiments,the purification state is tracked as a Boolean value as only 0 or 1.According to process 600 a water volume is preferably considered to beclean only when the water volume has resided in one or more effectivepurification beds for a total residence time equal to a full residencetime threshold. For example, when an unclean water volume (PS=1) residesin a first effective purification bed for half of the residence timethreshold and resides in a second effective purification bed for anotherhalf of the residence time threshold, the purification state may beconsidered to be clean (PS=0) upon evacuation from the second effectivepurification bed.

The tracking process 600 may overestimate the loading of thepurification bed X to preferably maintain a margin of safety inpreventing unclean water from reaching the environment. The process 600may track the bed loading state in integers, for example, integersranging from LS=0 (no bed loading) to LS=100 (ineffective if the bedloading threshold is 100). Accordingly, the bed loading state iseffective for LS=0 through LS=99. The bed loading state may beincremented (+1), for example, with each increment representing theabsorption of the hydrocarbons of one full water volume into thepurification bed X. However, if a water volume Y exits the purificationbed X before the residence time threshold is reached, the bed loadingstate of the purification bed X is still incremented (LS=LS+1) eventhough the full amount of hydrocarbons from the water volume Y may nothave been absorbed into the purification bed X. The bed loading state isalso incremented (LS=LS+1) when the water volume Y exits thepurification bed X after a full residence time threshold. Thus, the bedloading state of the purification bed X may be overestimated.

In many illustrative embodiments, upon the new water volume entering thewater filter, a current purification state may be updated forpurification bed X from the purification state of the upstreampurification bed X−1 in step 603. Further, the current purificationstate of the purification bed tracker associated with the firstpurification bed (X=1) may be updated to unclean (PS=1) in step 604indicating that the new water volume has a full amount of hydrocarbons.

In step 605, whether the current water volume Y is clean or not isdetermined in step 605. For example, if the purification state is clean(PS=0), then the water volume is determined to include clean water. Ifthe water volume is not clean, whether the current bed loading thresholdof purification bed X has been reached (has become ineffective) isdetermined in step 607.

If the current bed loading state has reached a bed loading threshold, afault state may be updated to indicate that the purification bed X hasreached the bed loading threshold (is ineffective) in step 608. Thepurification state and the residence time are preferably not updated,because as long as the water volume Y remains in the ineffectivepurification bed X, the water volume Y will not be further purified.However, if the current bed loading state has not reached the bedloading threshold (is effective), the current residence time of thecurrent water volume Y is updated in step 609 (for example, isincremented by one hour).

After step 609, whether the current residence time is equal to orgreater than a residence time threshold in purification bed X isdetermined in step 610. If the current residence time is meets orexceeds the residence time threshold, the current purification state maybe updated to clean in step 611. Furthermore, the current bed loadingstate may be incremented in step 613 to indicate that the hydrocarbonsin one water volume have been absorbed into purification bed X.

However, if the current residence time is less than the residence timethreshold, whether another water volume is ready to evacuate isdetermined in step 612. If the next evacuation is not ready, whether thewater volume is clean is checked in a loop back to step 605.

However, if the next evacuation is ready, the water volume Y may beevacuated. Further, the current bed loading state may be incremented(LS=LS+1) in step 613 to overestimate the amount of hydrocarbons thathave been absorbed into the purification bed X. Furthermore, the currentwater volume Y may be evacuated from the purification bed X before theresidence time threshold has been reached, and the water volume Y isstill considered unclean (PS=0).

After any of steps 605, 608, or 613, the process is then finished atstep 614. The process 600 may be repeated, however, each time a newvolume of water is evacuated. In this manner, each water volume in thewater filter may be tracked for purity based on residence time and eachpurification bed may be tracked until the end of its useful service lifebased on water volumes cleaned.

FIG. 10 is a schematic diagram view showing an illustrative process 700for tracking a purification state and a bed loading state in a watervolume tracker as water volumes advance through an illustrative waterfilter. In many embodiments, water volume in the water filter may beassociated with a different water volume tracker and, at any given time,a different purification bed. More specifically, a new water volumetracker may be created each time a new water volume enters the waterfilter.

In the illustrated embodiment, the water volume tracker keeps track of awater volume Y as it advances through various purification beds X. Forexample, process 700 may begin with a water evacuation in step 701. Thismay cause the water volume Y to exit a previous purification bed X−1 ina downstream direction and to enter a current purification bed X in step702.

In many illustrative embodiments, the water volume tracker maintainsparameters, such as a current residence time of the associated watervolume Y, a current purification state of the associated water volume Y,a current purification bed X in which the associated water volumeresides, and a current bed loading state of the current purification bedX. The parameters may be stored in a data structure, such as a table,which may be updated by the process 700.

The process 700 may track the purification state of the water volume Yin a range between 0 and 1, for example, in increments of tenths (0.1)with PS=0 representing a clean state and PS=1 representing an uncleanstate. According to process 700 a water volume is preferably consideredto be clean only when the water volume has resided in one or moreeffective purification beds for a total residence time equal to a fullresidence time threshold.

In particular, the process 700 may maintain a data structure (forexample, table) representing the kinetic profile of one or morepurification beds. Each table may associate a series of residence timethresholds (indexed by T_(R)), representing the time a water volume Yspends in an effective purification bed, with a series of purificationstates (PS), representing the normalized concentration of hydrocarbonsestimated to be remaining in the water volume (for example, water volumepurity). Each kinetic profile may be determined based on associatedkinetic parameters for each purification bed. In one illustrativeexample, a table representing the kinetic profile may associate:

0 hour residence time threshold (T_(R)=0) and 100% hydrocarbonsremaining (PS=1);

1 hour residence time threshold (T_(R)=1) and 20% hydrocarbons remaining(PS=0.2);

3 hours residence time threshold (T_(R)=2) and 10% hydrocarbonsremaining (PS=0.1); and

6 hours residence time threshold (T_(R)=3) and 0% hydrocarbons remaining(PS=0).

In various embodiments, the difference between residence time thresholdsand the purification states may define various purification changes overtime. In one example, the rate of hydrocarbon absorption may be higherbetween hours 0 and 1 (for example, 80% hydrocarbon removed per hour)than between hours 1 and 3 (for example, 5% hydrocarbon removal perhour). In other words, each subsequent purification changes over timemay be less than an immediately preceding purification change over timein some embodiments. Purification changes over time may depend onkinetic or adsorption isotherm parameters, such as the temperature andthe type of absorber material in the purification bed. Different tablesmay be used to represent different sets of kinetic and adsorptionisotherm parameters for one or more purification beds.

In many illustrative embodiments, the purification state for watervolume Y (PS) may be updated whenever the total residence time reaches aresidence time threshold (T_(R)). Even when a water volume Y isevacuated before a next residence time threshold is reached, the watershot tracker may continue to update a residence time in a timer, forexample, to keep track of the total residence time in the next effectivepurification bed X+1.

The process 700 may track the bed loading state for purification bed Xfrom LS=0 (no bed loading) to LS=100 (ineffective if the bed loadingthreshold is 100) in tenths (0.1) instead of whole integers. Because theamount of hydrocarbons removed from the water volume Y is tracked intenths (0.1), the difference between purification states may be used toincrement the bed loading. For example, once a total residence time ofthe water volume Y reaches 1 hour, the current purification state may bereduced from PS=1 to PS=0.2 and the bed loading state for purificationbed X may be increased by the difference (LS=LS+0.8).

The process 700 may overestimate the bed loading states, for example, byincrementing the bed loading state if a water volume Y is evacuatedbefore the next loading threshold is reached. For example, a watervolume tracker for the water volume Y that enters purification bed X at0 hours and leaves after only 30 minutes may increment the current bedloading state as if the water volume Y resided in the purification bed Xuntil the next residence time threshold at 1 hour (LS=LS+0.8). In thismanner, the process 700 may provide a margin of safety in preventing theevacuation of unclean water from the water filter.

In many illustrative embodiments, upon a new water volume entering thewater filter, the current purification bed for water volume Y may beupdated from X−1 to X in step 703. Further, a water volume tracker maybe created and associated with the new water volume having a currentpurification bed associated with the first purification bed (X=1) andthe purification state being not clean (PS=1) in step 704.

In step 705, whether the current water volume Y is clean is determined.For example, if the purification state is clean (PS=0), then the watervolume is determined to include clean water. If the water volume is notclean, whether the current bed loading threshold of purification bed Xhas been reached (has become ineffective) is determined in step 707.

If the current bed loading state has reached a bed loading threshold, afault state may be updated to indicate that the purification bed X hasreached a bed loading threshold (is ineffective) in step 708. Thepurification state and the residence time are preferably not updated,because as long as water volume Y remains in the ineffectivepurification bed X, the water volume Y will not be further purified.However, if the current bed loading state has not reached the bedloading threshold (is effective), the current residence time of watervolume Y is updated in step 709 (for example, is incremented by onehour).

After step 709, whether another water volume is ready to evacuate isdetermined in step 710. If the next evacuation is ready, the watervolume Y may be evacuated. Further, the current bed loading state may beincremented (LS=LS+PS(T_(R))−PS(T_(R)+1)) in optional step 711 tooverestimate the amount of hydrocarbons that have been absorbed into thepurification bed X. Still further, the water volume Y may enterpurification bed X+1 and whether the bed loading limit of purificationbed X+1 has been reached is determined in a loop back to step 707 (notillustrated), and the purification bed X+1 may be considered the currentpurification bed X in subsequent steps of the process 700.

However, if the next evacuation is not ready, whether the currentresidence time is equal to or greater than the next residence timethreshold (T_(R)+1) is determined in step 712. If the current residencetime meets or exceeds the residence time threshold, the currentpurification state may be updated to a next purification state(PS=PS(T_(R)+1)) associated with the next residence time threshold(T_(R)+1) in step 713.

Further, the bed loading state (LS) for purification bed X may beincremented accordingly in step 714 (LS=LS+PS(T_(R))−PS(T_(R)+1)). Forexample, the bed loading state (LS) may be incremented by the differencebetween the purification state of the current residence time threshold(PS(T_(R))) and the purification state of the next residence timethreshold (PS(T_(R)+1)). After step 714, whether the water volume Y isclean is determined in a loop back to step 705.

After any of step 705, 708, the process is then finished at step 715.The process 700 may be repeated, however, each time a new volume ofwater is evacuated. In this manner, each water volume in the waterfilter may be tracked for purity based on residence time and eachpurification bed may be tracked until the end of its useful service lifebased on water volumes cleaned.

Some of the advantages of the disclosed systems and constructions arefurther illustrated by the following example. The particular materials,amounts and dimensions recited in this example, as well as otherconditions and details, should not be construed to unduly limit thepresent disclosure.

EXAMPLES

Determination of Saturation and Polishing Capacities

The Freundlich Isotherm constants, K_(f) and 1/n, are fitting constantsthat indicate the extent of interaction between the adsorbate andadsorbent. In this example the filter is designed to remove dieselhydrocarbons from water. In a typical experiment the adsorbentproperties of various materials were determined as follows. Variousmasses of each material (50 mg-500 mg) were challenged with 20 mL of aB5 diesel fuel-in-water dispersion (typically 1000-2500 ppm hydrocarboncontent). The samples were equilibrated overnight and the equilibriumhydrocarbon concentration for each sample was determined using GC-MS(Gas Chromatography-Mass Spectrometry) relative to an n-hexadecane (C16)standard. The data was worked up using a linearized form of theempirical Freundlich isotherm expression:

${\log_{10}q} = {{\log_{10}\frac{x}{m}} = {{\log_{10}K_{f}} + {\frac{1}{n}\log_{10}c_{e}}}}$where q is the adsorbent loading in mg of hydrocarbons/g adsorbent(x/m), c_(e) is the equilibrium hydrocarbon concentration in the water,and K_(f) and 1/n are the isotherm parameters that are materialdependent and temperature dependent. In a multi-component adsorbate,such as diesel fuel, the isotherm parameters tended to be dependent onthe initial fuel-in-water dispersion concentration. Isotherms constantsand capacity values for a variety of materials are presented in Table 1(materials challenged with 2500 ppm B5 diesel fuel-in-water dispersion)and Table 2 (materials challenged with 1000 ppm B5 diesel fuel-in-waterdispersion).

TABLE 1 Freundlich Isotherm Constants for Materials Challenged with 2500ppm B5 Diesel Fuel-in-Water dispersion Material Capacity FreundlichIsotherm (mg hydrocarbon/gram material) Constants Polishing, q_(t)Saturation, q_(sat) Material Log K_(f) 1/n (c_(e) = 2 ppm) (c_(e) = 2500ppm) Norit GCN 1240 1.29 0.43 26.4 568 Silcarbon K48 0.00 0.86 1.8 854Norit ROW 0.8 1.69 0.45 67 1613 Supra Obermeier TyP 1.36 0.43 31 661Aqua S816 Chemviron 1.99 0.30 119 981 Carbosrb 28FB Calgon Filtersorb1.88 0.31 94 853 F300 Calgon Filtersorb 1.55 0.46 49 1356 F400

TABLE 2 Freundlich Isotherm Constants for Materials Challenged with 1000ppm B5 Diesel Fuel-in-Water dispersion Freundlich Material CapacityIsotherm (mg hydrocarbon/gram material) Constants Polishing, q_(t)Saturation, q_(sat) Material Log K_(f) 1/n (c_(e) = 2 ppm) (c_(e) = 1000ppm) Chemviron 1.54 0.40 45.7 561 Carbsorb 28FB Polyurethane foam −2.692.08 0.0^(a) 3686 (Restek; Catalog #22957) ^(a)The polyurethane foamcannot purify water down to 2 ppm, according to the Freundlich Isothermparameters.

Norit GCN 1240 is commercially available from Cabot Corporation (Boston,Mass.).

Silcarbon K48 is commercially available from Silcarbon Aktivkohle GmbH(Kirchhundem, Germany).

Norit ROW 0.8 Supra is commercially available from Cabot Corporation(Boston, Mass.).

Obermeier TyP Aqua 5816 is commercially available from Kurt ObermeierGmbH & Co. (Bad Berleburg, Germany).

Chemviron Carbosrb 28FB is commercially available from Chemviron Carbon(Feluy, Belgium).

Calgon Filtersorb F300 is commercially available from Calgon CarbonCorporation (Moon Township, Pa.).

Calgon Filtersorb F400 is commercially available from Calgon CarbonCorporation (Moon Township, Pa.).

Example A

The adsorbent properties of a high capacity carbon (Silcarbon K48) and apolishing carbon (Norit GCN 1240) were determined by running an isothermexperiment as described previously. Isotherm parameters for a 2500 ppmB5 diesel fuel-in-water dispersion challenge are presented in Table 1.The target cleanliness for this example is 2 ppm.

As observed, the Silcarbon K48 carbon has a higher saturation capacity,whereas the Norit GCN 1240 carbon has a higher loading capacity whentargeting an outlet hydrocarbon concentration of 2 ppm. Therefore, ahydrocarbon in water purification system including Silcarbon K48 highcapacity stage followed by a Norit GCN 1240 polishing stage will have alonger lifetime than an equal mass system including only Norit GCN 1240polishing carbon.

By breaking the absorbent bed into two stages, where the first uses ahigh capacity material and the second stage uses a polishing material,we can increase the lifetime of a water purification filter. Calculatedresults verify this increase in lifetime when the bed is challengedsequentially with 50 mL water samples that have an initial hydrocarbonconcentration of 2500 ppm. In this model the water and carbon areallowed to equilibrate completely according to the Freundlich Isothermexpression before being transferred to the next filter stage or byleaving the element. The Freundlich isotherm parameters for the highcapacity material and polishing material are based off of isothermexperiments using diesel fuel-in-water dispersion challenge (Table 1).This model was used in all examples. In this example both materials wereactivated carbons.

A filter containing 357 g of Norit GCN 1240 will purify 68 L of waterbefore breaking through the target concentration of 2 ppm. By breakingthe filter into two stages of Silcarbon K48 (high capacity) and NoritGCN1240 (polishing) the optimal lifetime in the multi-batch model is 60%by weight high capacity carbon, and 40% by weight polishing carbon. Inthis ratio the will purify 82 L before breakthrough at 2 ppm. This is a21% increase in hydrocarbon absorber filter lifetime.

Example B

A filter containing 357 g of Chemviron Carbsorb 28FB will purify 112 Lof water before breaking through the target concentration of 2 ppm. Bybreaking the filter into two equal mass stages of Norit ROW 0.8 Supra(high capacity carbon) and Carbsorb 28FB (polishing carbon), thelifespan of the filter is increased to 148 L of water. Further improvingthe system finds that the optimal life in the multi-batch model is 90%by weight high capacity carbon, and 10% by weight polishing carbon.These ratios may differ for different specific adsorbents. In this ratiothe filter will purify 167 L before breakthrough at 2 ppm. This is a 49%increase in hydrocarbon absorber filter lifetime.

Example C

In another example of high capacity materials, a typical polishingcarbon was compared to a polyurethane foam (Restek; Catalog #22957). Thepolyurethane and polishing carbon were challenged with 1000 ppmhydrocarbons (B5) in water dispersion to determine the FreundlichIsotherm parameters Log K and 1/n (Table 2). From these values theloading at saturation and at a target cleanliness (polishing) arecomputed. Here the target cleanliness is 2 ppm hydrocarbons in water.From experimental data, the Restek polyurethane cannot purify the waterdown to the intended cleanliness alone (q_(t)=0 mg hydrocarbons/gmaterial). In contrast, the typical polishing carbon has a capacity ofq_(t)=45.7 mg hydrocarbon/gram of carbon at the 2 ppm targetcleanliness.

The Restek polyurethane has a significantly higher saturation capacitythan the polishing carbon (Restek polyurethane: q_(sat)=3686 mghydrocarbons/g material; polishing carbon: q_(sat)=561 mg hydrocarbons/gmaterial). Thus a two-stage filter having a high-capacity polymer stagefollowed by a polishing carbon has a longer expected lifetime than afilter of carbon alone.

For example, in a multi-batch application (challenge water=1000 ppmhydrocarbons in water) a calculated lifetime of a 250 g polishing carbonelement is 112 L of before breaking through the target concentration of2 ppm. A filter element designed using 50 g of Restek polyurethanefollowed by 200 g of polishing carbon has a calculated lifetime to 132 Lbefore breakthrough. This is an 18% increase in hydrocarbon absorberfilter lifetime.

The order of the absorbent stages is important to increase the overalllifetime of the hydrocarbon in water purification system. If the stagesin the previous example are reversed (200 g polishing carbon followed by50 g of Restek polyurethane) the lifetime of the system is decreased to80 L before breakthrough. This is a 29% decrease in hydrocarbon absorberfilter lifetime.

Example D

A multi-batch application filter has a high capacity stage of 120 g ofCalgon Filtersorb F400 carbon followed by a polishing stage of 60 g ofChemviron Carbsorb 28FB. The filter is challenged with sequential 40 mLvolumes of 2500 ppm hydrocarbon (B5 diesel fuel)-in-water dispersions.The filter will purify 64 L of water before breaking through at 2 ppmhydrocarbon content. This is an increase in lifetime of 28% over anequivalent mass filter containing only polishing material (50 Llifetime).

The increase in lifetime occurs over a range of water purificationtargets. If the maximum hydrocarbon concentration allowed to leave thebed is 20 ppm the high capacity/polishing filter described above willpurify 69 L of water before breakthrough. This is an increase inlifetime of 28% over an equivalent mass filter containing only polishingmaterial (54 L lifetime).

Alternatively, if the filter includes a high capacity stage of 120 g ofNorit ROW 0.8 Supra carbon followed by a polishing stage of 60 g ofChemviron Carbsorb 28FB the filter will purify 70 L of water beforebreaking through at 2 ppm hydrocarbon content. This is an increase inlifetime of 40% over an equivalent mass filter containing only polishingmaterial (50 L lifetime).

Example E

A multi-batch application filter has a high capacity stage of 70 g ofNorit Row 0.8 Supra carbon followed by a polishing stage of 70 g ofChemviron Carbsorb 28FB carbon. The filter is challenged with sequential50 mL volumes of 1000 ppm hydrocarbon (B5 diesel fuel)-in-waterdispersion. The filter will purify 80 L of water before breaking throughat 5 ppm hydrocarbon content. This is an increase in lifetime of 36%over an equivalent mass filter containing only polishing material (59 Llifetime)

Example F

A multi-batch application filter has a high capacity stage of 140 g ofSilcarbon K48 carbon followed by a polishing stage of 140 g of ObermeierTyP Aqua 5816. The filter is challenged with sequential 50 mL volumes of2500 ppm hydrocarbon (B5 diesel fuel)-in-water dispersion. The filterwill purify 64 L of water before breaking through at 2 ppm hydrocarboncontent. This is an increase in lifetime of 8% over an equivalent massfilter containing only polishing material (59 L lifetime).

Example G

A multi-batch application filter has a high capacity stage of 30 g ofpolyurethane foam (Restek; Catalog #22957) followed by a polishing stageof 60 g of Obermeier TyP Aqua S816. The filter is challenged withsequential 40 mL volumes of 2500 ppm hydrocarbon (B5 dieselfuel)-in-water dispersion. The filter will purify 18 L of water beforebreaking through at 2 ppm hydrocarbon content. This is an increase inlifetime of 50% over an equivalent mass filter containing only polishingmaterial (12 L lifetime).

Example H

A filter design that starts with a high capacity material can have thelifetime increased by replacing the downstream portion of the filterwith a polishing material. For example, a filter is designed to purifysequential 10 mL volumes of 1000 ppm hydrocarbon (B5 dieselfuel)-in-water dispersion. A filter including 37.5 g of high capacitymaterial (Norit ROW 0.8 Supra) will purify 26 L of water before breakingthrough at 5 ppm hydrocarbon content. Changing the design to include 30g of high capacity carbon material followed by 7.5 g of polishingmaterial (Calgon Filtersorb F300) increased the lifetime to 29 L ofwater purification. This is an increase in lifetime of 12%.

Example I

A multi-batch application filter has a high capacity stage of 150 g ofpolyurethane foam (Restek; Catalog #22957) followed by a polishing stageof 150 g of Norit ROW 0.8 Supra carbon. The filter is challenged withsequential 100 mL volumes of 2500 ppm hydrocarbon (B5 dieselfuel)-in-water dispersion. The filter will purify 131 L of water beforebreaking through at 10 ppm hydrocarbon content. This is an increase inlifetime of 24% over an equivalent mass filter containing only polishingmaterial (106 L lifetime).

Example J

A multi-batch application filter has a high capacity stage of 2.25 kg ofNorit ROW 0.8 Supra carbon followed by a polishing stage of 3.75 kgChemviron Carbsorb 28FB carbon. The filter is challenged with sequential1 L volumes of 1500 ppm hydrocarbon (B5 diesel fuel)-in-waterdispersion. The filter will purify 3260 L of water before breakingthrough at 1 ppm hydrocarbon content. This is an increase in lifetime of31% over an equivalent mass filter containing only polishing material(2490 L lifetime).

Example K

The filter from Example J can be further enhanced by using multiple highcapacity materials in series. The high capacity stage in the filterabove is changed to contain 750 g of polyurethane foam (Restek; Catalog#22957) followed by 1.5 kg of Norit Row 0.8 Supra carbon; the polishingstage is unchanged. The filter is challenged with sequential 1 L volumesof 1500 ppm hydrocarbon (B5 diesel fuel)-in-water dispersion. The filterwill purify 4137 L of water before breaking through at 1 ppm hydrocarboncontent. This is an increase in lifetime of 66% over an equivalent massfilter containing only polishing material (2490 L lifetime). If the highcapacity stage is only polyurethane foam the lifetime is decreased to3760 L.

Example L

A multi-batch application filter has a high capacity stage of 70 g ofCalgon Filtersorb F400 carbon followed by a polishing stage of 70 g ofChemviron Carbsorb 28FB carbon. The filter is challenged with sequential50 mL volumes of 500 ppm hydrocarbon (B5 diesel fuel)-in-waterdispersion. The filter will purify 106 L of water before breakingthrough at 10 ppm hydrocarbon content. This is an increase in lifetimeof 8% over an equivalent mass filter containing only polishing material(98 L lifetime).

Example M

The high capacity stage in Example L was replaced with 70 g of Norit ROW0.8 Supra carbon; the polishing stage is unchanged. The filter ischallenged with sequential 50 mL volumes of 500 ppm hydrocarbon (B5diesel fuel)-in-water dispersion. The filter will purify 120 L of waterbefore breaking through at 10 ppm hydrocarbon content. This is anincrease in lifetime of 22% over an equivalent mass filter containingonly polishing material (98 L lifetime).

Example N

The high capacity stage in Example M was increased to 105 g. Thepolishing stage was decreased to 35 g. The filter is challenged withsequential 50 mL volumes of 500 ppm hydrocarbon (B5 dieselfuel)-in-water dispersion. The filter will purify 101 L of water beforebreaking through at 500 ppb hydrocarbon content. This is an increase inlifetime of 42% over an equivalent mass filter containing only polishingmaterial (74 L lifetime).

Thus, embodiments of HYDROCARBON-IN-WATER PURIFICATION SYSTEM aredisclosed. One skilled in the art will appreciate that the purificationsystems described herein can be practiced with embodiments other thanthose disclosed. The disclosed embodiments are presented for purposes ofillustration and not limitation.

The invention claimed is:
 1. A method comprising: determining whether apurification state of a dischargeable water volume in a finalpurification bed in a water filter is clean or not clean by comparing acurrent residence time to a residence time threshold, wherein the waterfilter contains one or more water volumes and a plurality ofpurification beds arranged from a first purification bed to the finalpurification bed such that the first purification bed receives new waterintroduced into the water filter from a water collection reservoir andthe final purification bed discharges water from the water filter,wherein the one or more water volumes reside in the plurality ofpurification beds; in response to determining that the purificationstate of the dischargeable water volume is clean, controlling a fuelpump to operate in reverse for a predetermined amount of time toevacuate a new water volume from the water collection reservoir;introducing the new water volume into the first purification bed inresponse to the evacuation, wherein introducing the new water volumemoves each of the one or more water volumes in the water filter suchthat the dischargeable water volume leaves the final purification bedand a next dischargeable water volume of the one or more water volumesenters the final purification bed; tracking a purification stateassociated with the next dischargeable water volume in response to aresidence time of the next dischargeable water volume in at least one ofthe purification beds; and tracking a bed loading state associated withthe at least one of the purification beds in response to the residencetime.
 2. The method according to claim 1 further comprising: receiving atemperature sensor signal; determining whether a water temperature isbelow a low temperature threshold based on the temperature sensor signalprior to determining whether the purification state of the dischargeablewater volume is clean; and bypassing the steps of controlling the fuelpump and introducing the new water volume in response to determiningthat the water temperature is below the low temperature threshold. 3.The method according to claim 1 further comprising: determining whetherthe bed loading state associated with the at least one of thepurification beds exceeds a bed loading threshold associated with the atleast one purification bed in response to the step of introducing thenew water volume; and updating a fault state to filter expired inresponse to determining that one or more of the plurality ofpurification beds have bed loading states exceeding the associated bedloading thresholds.
 4. The method according to claim 3 furthercomprising: updating the fault state in response to at least onecondition indicating that the new water volume cannot be evacuated fromthe water collection reservoir.
 5. The method according to claim 1further comprising: determining that the new water volume is ready toevacuate from the water collection reservoir and into the water filterbased on a sensed water level in the water collection reservoir: andintroducing the new water volume into the first purification bed fromthe water collection reservoir in response to the new water volume beingready to evacuate.
 6. The method according to claim 1 furthercomprising: updating a purification bed tracker defining an associatedpurification bed corresponding to one of the plurality of purificationbeds in response to introducing the new water volume, wherein thepurification bed tracker maintains a current residence time of a currentwater volume residing in the associated purification bed, a currentpurification state of the current water volume, and a current bedloading state of the associated purification bed, wherein each of theplurality of purification beds is associated with a differentpurification bed tracker and a different water volume, wherein thecurrent purification state of the purification bed tracker associatedwith the first purification bed is updated to unclean.
 7. The methodaccording to claim 6 wherein updating the purification bed tracker forassociated purification beds other than the first purification bedcomprises: determining another current purification state correspondingto the current purification state of the purification bed tracker fromwhich the current water volume previously resided prior to introducingthe new water volume; and setting the current purification state of thepurification bed tracker to another current purification state.
 8. Themethod according to claim 6 further comprising: determining whether thecurrent purification state of the current water volume is clean or notclean by comparing a current residence time to a residence timethreshold; and determining whether the current bed loading state of theassociated purification bed has reached an associated bed loadingthreshold or not in response to determining that the currentpurification state of the current water volume is not clean.
 9. Themethod according to claim 8 further comprising updating the currentresidence time in response to determining that the current bed loadingstate has not reached the associated bed loading threshold.
 10. Themethod according to claim 9 further comprising: determining whether thecurrent residence time is equal to or greater than a residence timethreshold; and updating the current purification state to clean inresponse to determining that the current residence time is equal to orgreater than the residence time threshold.
 11. The method according toclaim 10 further comprising incrementing the current bed loading stateof the associated purification bed to indicate cleaning of the currentwater volume by the associated purification bed in response todetermining that the current residence time is equal to or greater thanthe residence time threshold.
 12. The method according to claim 10further comprising incrementing the current bed loading state of theassociated purification bed in response to a signal indicating thatanother new water volume is ready to evacuate from the water collectionreservoir before the current residence time is equal to or greater thanthe residence time threshold.
 13. The method according to claim 10further comprising: updating the current residence time in response todetermining that the current residence time is less than the residencetime threshold and a signal indicating that another new water volume isnot ready to evacuate.
 14. The method according to claim 1 furthercomprising: updating a water volume tracker defining an associated watervolume corresponding to one of the water volumes in response tointroducing the new water volume, wherein the water volume trackermaintains a current residence time of the associated water volume, acurrent purification state of the associated water volume, a currentpurification bed in which the associated water volume resides, and acurrent bed loading state of the current purification bed, wherein eachof the one or more water volumes is associated with a different watervolume tracker and a different purification bed; and creating a watervolume tracker associated with the new water volume.
 15. The methodaccording to claim 14 further comprising: determining whether thecurrent purification state of the associated water volume is clean ornot clean by comparing a current residence time to a residence timethreshold; and determining whether the current bed loading state of thecurrent purification bed has reached an associated bed loading thresholdor not in response to determining that the current purification state ofthe associated water volume is not clean.
 16. The method according toclaim 15 further comprising updating the current residence time inresponse to determining that the current bed loading state has notreached the associated bed loading threshold.
 17. The method accordingto claim 15 further comprising: determining whether the currentresidence time is equal to or greater than a next residence timethreshold; and updating the current purification state to a nextpurification state indicating an amount of hydrocarbons in theassociated water volume associated with the next residence timethreshold defining a first purification change over time in response todetermining that the current residence time is equal to or greater thanthe next residence time threshold.
 18. The method according to claim 17further comprising: determining whether a subsequent current residencetime is equal to or greater than a subsequent next residence timethreshold in response to updating the current purification state to thenext purification state; and updating the current purification state toa subsequent next purification state indicating an amount ofhydrocarbons in the associated water volume associated with thesubsequent next residence time threshold and defining a secondpurification change over time in response to determining that thesubsequent current residence time is equal to or greater than thesubsequent next residence time threshold, wherein the secondpurification change over time is less than the first purification changeover time.
 19. The method according to claim 17 further comprisingupdating the current bed loading state of the current purification bedby a next bed loading increment associated with the next residence timethreshold to indicate cleaning of a water volume by the currentpurification bed in response to determining that the current residencetime is equal to or greater than the next residence time threshold. 20.The method according to claim 19 wherein the next bed loading incrementis equal to the first purification change over time.
 21. The methodaccording to claim 17 further comprising determining whether the currentpurification state of the associated water volume is clean or not cleanby comparing a current residence time to a residence time threshold inresponse to updating the current purification state.
 22. A methodcomprising: controlling a fuel pump to operate in reverse for apredetermined amount of time to evacuate a new water volume from a watercollection reservoirs; introducing the new water volume into a firstpurification bed of a water filter in response to the evacuation,wherein the water filter contains one or more water volumes and aplurality of stacked purification beds arranged from the firstpurification bed to a final purification bed such that the firstpurification bed receives new water introduced into the water filterfrom the water collection reservoir and the final purification beddischarges water from the water filter, wherein the one or more watervolumes reside in the plurality of purification beds; updating apurification bed tracker defining an associated purification bedcorresponding to one of the plurality of purification beds in responseto the introduction of the new water volume, wherein the purificationbed tracker maintains a current residence time of a current water volumeresiding in the associated purification bed, a current purificationstate of the current water volume, and a current bed loading state ofthe associated purification bed, wherein each of the plurality ofpurification beds is associated with a different purification bedtracker and a different water volume; and updating the currentpurification state of the purification bed tracker associated with thefirst purification bed to unclean.
 23. A method comprising: controllinga fuel pump to operate in reverse for a predetermined amount of time toevacuate a new water volume from a water collection reservoirs;introducing the new water volume into a first purification bed of awater filter in response to the evacuation, wherein the water filtercontains one or more water volumes and a plurality of purification bedsarranged from the first purification bed to a final purification bedsuch that the first purification bed receives new water introduced intothe water filter from the water collection reservoir and the finalpurification bed discharges water from the water filter, wherein the oneor more water volumes reside in the plurality of purification beds;updating a water volume tracker defining an associated water volumecorresponding to one of the water volumes in response to theintroduction of the new water volume, wherein the water volume trackermaintains a current residence time of the associated water volume, acurrent purification state of the associated water volume, a currentpurification bed in which the associated water volume resides, and acurrent bed loading state of the current purification bed, wherein eachof the one or more water volumes is associated with a different watervolume tracker and a different purification bed; and creating a watervolume tracker associated with the new water volume with the currentpurification state of the new water volume set to unclean.